Helical acting straight snap roll flutes for corn header

Abstract

A helical-acting snap roll for a harvesting header having straight flutes which are free of a formed twist. The snap roll includes elongated straight flutes that extend substantially the entire length of the snap roll but that are parallel misaligned with a central axis of rotation of the snap roll. A pair of opposing and counter-rotating snap rolls of the present invention chops and pulls crop stalks passing therebetween downward toward the ground while also creating a helical action such that the crop stalks are conveyed rearward.

What is claimed is: 
     
       1. A first snap roll in combination with a second snap roll for harvesting stalk crops wherein said first and second snap rolls have outer surfaces that each comprise a plurality of flat sides, and first and second pluralities of straight chopping portions extending from flat members mounted on said first and second snap rolls, respectively, each of said straight chopping portions substantially straight relative at least most of their length and misaligned with a central axis of rotation of its respective snap roll such that each flat member on said straight chopping portions extends diagonally across a corresponding one of said flat sides, said first and second snap rolls opposing one another and when counter rotating a portion of one of said straight chopping portions of said first snap roll works along a portion of a corresponding one of said straight chopping portions of said second snap roll to define a point for engaging crop stalks between said corresponding straight chopping portions and as said first and second snap rolls counter rotate said point moves from leading ends of said first and second snap rolls toward trailing ends of said first and second snap rolls, said corresponding straight chopping portions separating from one another following said point as said point moves from leading ends to trailing ends of said straight chopping portions of said first and second snap rolls. 
     
     
       2. The first and second snap rolls of  claim 1  wherein during one revolution of said first and second snap rolls said point runs substantially the entire lengths of said corresponding straight chopping portions. 
     
     
       3. The first and second snap rolls of  claim 1  wherein each of said straight chopping portions of said first snap roll corresponds with a respective one of said straight chopping portions of said second snap roll during a single rotation of each of said first and second snap rolls. 
     
     
       4. The first and second snap rolls of  claim 1  wherein said corresponding straight chopping portions are continuously displaced from one another until working against one another again at leading edges of said corresponding straight chopping portions during a subsequent rotation of said first and second snap rolls. 
     
     
       5. The first and second snap rolls of  claim 1  wherein another straight chopping portion of each of said first and second snap rolls correspond with each other to define another point wherein said other point moves from leading ends to trailing ends of said other straight portions of said first and second straight chopping portions. 
     
     
       6. The first and second snap rolls of  claim 1  further comprising a continuous scissors action at said point as said point moves. 
     
     
       7. The first and second snap rolls of  claim 1  wherein said first and second snap rolls each comprise an outer surface with said first and second plurality of straight chopping portions extending from said respective outer surfaces, distal edges of each of said straight chopping portions of said first snap roll extending from said outer surface of said first snap roll such to oppose distal edges of each corresponding said second plurality of straight portions. 
     
     
       8. The first and second snap rolls of  claim 1  wherein counter-rotation of said first and second snap rolls chops and pulls crop stalks passing therebetween downward toward the ground while also creating a helical action with said first and second plurality of straight chopping portions such that the crop stalks are conveyed rearward. 
     
     
       9. The first and second snap rolls of  claim 1  wherein an outer surface of each of said first and second snap rolls is other than round. 
     
     
       10. The first and second snap rolls of  claim 9  wherein said outer surfaces each comprise a plurality of sides, each said straight chopping portion extending diagonally across a corresponding one of said sides. 
     
     
       11. The first and second snap rolls of  claim 10  wherein each said side is flat. 
     
     
       12. The first and second snap rolls of  claim 1  wherein each said straight chopping portion includes a distal edge that is at least partially elliptical in shape. 
     
     
       13. The first and second snap rolls of  claim 1  wherein said first and second snap rolls are otherwise free of a twist. 
     
     
       14. The first and second snap rolls of  claim 1  wherein each of said first and second snap rolls comprises an outer surface defined by a plurality of sides and wherein a leading end of one of said straight chopping portions extends toward an edge of a corresponding one of said sides and a trailing end of said one straight portion extends toward another opposing edge of said corresponding one of said sides. 
     
     
       15. The first and second snap rolls of  claim 1  wherein said straight chopping portions of said first snap roll cooperate with said straight chopping portions of said second snap roll to chop crop stalks passing between said first and second snap rolls.